Hydraulic ice maker



Jan. 3H, WW1 D. w.JAcoBus ET AL 3,300,998

HYDRA ULI C I CE MAKER 2 Sheets-Sheet 1 Filed D66. 9, 1965 INVENTORS D\U\GHT W. 'IACOBUS &\U\L

B MAM BODOMG THEHZ ATTORNEY Jan. 31, 1967 U cogus ET AL 3,300,998

HYDRAULIC I CE MAKER 2 Sheets-Sheet 2 Filed Dec. 9, 1965 S Mmu m8 mm VT. W W T H w W D 8 WlLLlAM c. BoDowG /W/ ZJQ (HER ATTORNEY United States Patent 3,3009% HYDRAULIC ICE MAKER Dwight W. Iacobus and William C. Bodong, Louisville,

Ky., assignors to General Electric Company, a corporation of New York Filed Dec. 9, 1965, Ser. No. 512,723 9 Claims. (Cl. 62-135) The present invention relates to an automatic ice maker and is more particularly concerned with a hydraulic ice maker for operation in the freezer compartment of a household refrigerator.

Automatic ice makers for household refrigerators normally comprise means for sequentially and automatically filling one or more mold cavities with water, freezing the water to form ice pieces and discharging the formed pieces into a suitable container. The present invention has as its principal object the provision of an automatic ice maker including a hydraulically operated piston and water feed means for removing ice pieces from the mold and for automatically supplying a new charge of water to the mold.

Another object of the invention is to provide a new and improved ice maker in which a hydraulically powered ice ejecting means is actuated by a measured volume of water and means for introducing this volume of water into the mold after removal of the ice pieces therefrom.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In accordance with the illustrated embodiment of the present invention, there is provided an automatic ice maker including a mold structure for operation in a freezer compartment and including at least one ice cavity and an ice ejecting means comprising a cylinder and piston assembly. The cylinder is connected to a source of water under pressure. The cylinder and piston are cooled to below freezing temperatures during formation of ice in the mold whereby during this freezing cycle of operation of the ice maker, ice formed from residual water present in the cylinder freezes the piston against movement within the cylinder. Thawing of the ice bond between the piston and cylinder walls by energization of suitable heat ing means permits movement of the piston under the pres sure of the measured volume of water introduced into the cylinder to a position in which ice is ejected from the mold. Means including a water passage are provided for transferring the volume of water from the cylinder to the mold following removal of ice from the mold. This passage is normally closed or plugged by a body of ice formed therein during the freezing of the ice in the mold and is opened by the thawing of this ice plug following the ejection cycle so that removal of ice from the mold is assured before the introduction of a new charge of water into the mold.

For a better understanding of the invention reference may be had to the accompanying drawing in which:

FIGURE 1 is an elcvational view, partly in section, of the mold structure of the present invention;

FIGURE 2 is a vertical sectional view taken along lines 22 of FIGURE 1 illustrating certain components of the mold structure during the freezing stage of operation;

FIGURE 3 is a View similar to FIGURE 2 illustrating the position of these components following the ice ejection stage of operation;

FIGURE 4 is a sectional view taken along line 4-4 of FIGURE 1 illustrating the certain details of the mold cavity and related mold structure in the same stage of operation of the mold structure as that illustrated in FIG- URE 2;

FIGURE 5 is a sectional view similar to FIGURE 4 illustrating the same stage of operation as that illustrated in FIGURE 3;

FIGURE 6 is a perspective view of portions of the piston and ice ejecting means forming part of the mold struc ture; and

FIGURE 7 is a schematic illustration of the over-all ice maker and the control circuitry therefor.

Referring particularly to FIGURES 1, 2 and 3 of the drawing, the automatic ice maker of the present invention includes a metal mold block I mounted on a frame 2 which in turn is adapted to be secured to the wall 3 of a freezer compartment by means of a plurality of brackets 4. The illustrated mold block is designed to be cooled primarily by the below-freezing air within or circulated through the freezer compartment and to this end it is provided with a plurality of heat exchange fins 5.

The mold block includes a plurality of ice cavities 7. These ice cavities 7 are shown as being arranged in groups of threes on opposite sides of a cylinder 8 including an upper portion 9 which is at substantially the same elevation as the cavities 7 and a lower portion 10' extending below the plane of the cavities 7. The cavities 7 are separated from one another by walls 11 while the innermost cavities are separated from the upper portion of the cylinder 8 by walls 12. Each of these walls includes a vertical passage 14 which, as will be more fully described hereinafter, provide means for the flow of water from the cylinder 8 into the various ice cavities 7. Preferably, the cavities 7 are of a generally elliptical cross section and are of a larger cross sectional area at the top than at the bottom in order to permit easy ejection of ice pieces therefrom.

The cylinder 8 and a piston 16 contained within the cylinder provides hydraulic power means for ejecting the ice pieces from the cavities 7. During formation of ice pieces in the mold cavities, the piston 16, as is shown in FIGURE 2 of the drawing, is in its normal position with the bottom end 18 thereof adjacent to but spaced from the bottom wall 19 of the cylinder. An extended or upper portion 20 of the piston is normally disposed in in the upper portion 9 of the cylinder 8. Secured thereto, or forming an integral part thereof, are ejecting pad structures 22 shown in FIGURE 6 of the drawing. Each of these pad constructions 22 comprises a tapered vertical member 23 normally contained in the slots or passages 14 in the walls 12 dividing the upper portion of the cylinder from the adjacent cavities 7 and a horizontal arm 24 extending through the cavities 7 or more specifically through the remaining passages 14 and having thereon pads 25 respectively positioned at the bottoms of each of the cavities 7 during formation of the ice pieces.

The piston 16 is biased to its lower position within the cylinder 8 by means of a yoke 27 of inverted U-shape extending across the top surface of the upper portion 20 of the piston and biased downwardly by tension springs 28 connecting the yoke 27 to ears 29 forming part of a housing 30 which encloses-the lower or downwardly extending portion 10 of the cylinder 8. The housing 30 provides means for isolating or insulating this portion of 3 the mold structure from the freezer compartment ambient.

The ice maker also includes within the housing 30 a mold cavity heater 31 positioned adjacent the lower perimeters of the cavities 7 and a cylinder heater 32 in heating relationship with the lower portion of the cylinder 8. Also contained within the housing is a mold thermostat 34 and a safety thermostat 35 designed to prevent operation of the ice maker under abnormal mold temperature conditions.

A measured volume of water for operating the piston 16 to eject ice pieces from the mold and for filling the cavities 7 is supplied to the mold structure 1 through a supply line connecting the bottom wall 19 of the cylinder 8 with a measuring vessel 41 as shown in FIGURE 7 of the drawing. The measuring vessel, positioned outside the freezer compartment in an above freezing ambient, includes a water chamber 42 formed in part by a flexible rubber diaphragm cup 43. Water is supplied to the measuring vessel through a conduit 44 connected to a high pressure water source, such as a city water supply, under control of a normally closed solenoid valve 45. A plunger 46 hearing against the bottom of the diaphragm 43 and a compression spring 47 engaging the plunger 46 furnish the pressure required to operate the piston 16 when the valve is closed.

Means for conveying the measured volume of water from the cylinder 8 to the cavities 7 following an ejection cycle comprises a T-shaped passage 50 having its inlet 51 in the bottom surface of the piston 16 and a pair of outlets 52 in the vertical side walls of the piston 16 above a piston cup or seal 53 provided adjacent the bottom portion of the piston 16.

Control means and circuitry for automatically controlling the operation of the ice maker through its various cycles includes a toggle switch 54 and a switch operating arm 55 connected to the plunger 46 for operating the toggle switch 54 (FIGURE 7). The complete ice maker includes a bin switch 56 operable to interrupt the operation of the ice maker when a storage bin 57 or receptacle into which the ice pieces are discharged becomes filled.

Additional details of the ice maker and the control circuitry will be described in connection with the following description of the operation thereof:

In describing the operation of the ice maker, it will be assumed that the bin switch 56 is closed, and the mold is at a temperature such that the safety switch 35 is also closed, that the toggle switch arm 59 forming part of the toggle switch 54 is in engagement with the contact 60, the chamber 42 empty and the piston 16 is in its lower position. The mold heater thermostat switch 34 is open and a supply line heater 63 connected directly across the electric power lines 64 is energized to maintain the supply line 40 adjacent the cylinder 8 or in other words that portion of the supply line within the freezer compartment at above freezing temperatures.

As the temperature of the mold decreases to the point where the mold thermostat 34 senses a temperature indicating that a charge of water previously supplied to the mold cavities 7 has frozen, the mold heater thermostat 34 will close thereby energizing the solenoid valve 45 through a circuit which includes the mold heater thermostat 34 and the contact of the toggle switch 54 and the bin switch 56. Opening of the solenoid valve 45 allows water under pressure from the household water supply line 44 to enter the chamber 42 and displace the plunger 46 against the biasing action of the spring 47. When a predetermined volume of water has flown into the measuring vessel 41, a stop 66 on the arm 55 trips the switch arm 59 to open the circuit including the solenoid valve 45 and to complete a circuit through toggle switch contact 88 for energizing the mold heater 31 and the cylinder heater 32. Since the solenoid valve 45 and the heaters 31 and 32 are controlled by the toggle switch 54 which in turn is actuated by the plunger 46, in the event that the household water supply is temporarily insufficient to fill the measuring vessel 41 to its required volume, operation of the ice maker will be interrupted until such time as the required pressure has become available.

During filling of the chamber 42, the piston 16 does not move due to the fact that it is frozen to the inner surface of the cylinder 8 by a film of ice within the clearance 70 between the walls of the piston and the cylinder above the seal 53 and water is prevented from flowing through passage 50 to the cavities 7 by this film of ice as well as a plug of ice formed within passage 50.

Energization of the heaters 31 and 32 warms the walls of the cavities 7 and the cylinder 8 to release the ice pieces contained within the cavities 7 and melt the ice bond between the piston and cylinder walls. Preferably the mold heater 31 and the cylinder heater 32 are sized so that the ice pieces are thawed free of the cavity walls before the ice bond between the walls of the piston 16 and the cylinder 8 is broken.

The thawing of the ice bond between the piston and cylinder walls frees the piston for movement under the pressure of the water in the measuring vessel 41. The piston and the ejection structure 22 move upwardly to lift the ice pieces out of the cavities 7. As the piston 16 approaches its upper position, the ice pieces 75 are engaged by a sweep 76 pivotally supported on the frame. The sweep 76 is preferably inclined relative to the direction of travel of the ice pieces whereby the initial contact of the ice pieces with the sweep 76 breaks the ice pieces free of the pads 25 and adjacent portions of the ejection structure 22.

As the piston 16 continues to move towards its upper position where it engages the stop 78 on frame 2, as shown in FIGURE 3, the transverse portion 79 of the yoke 27 engages a finger 80 forming part of the sweep 76 whereby the sweep is caused to rotate about its pivot axis 81 and sweep the ice pieces from the top of the mold for discharge into the storage bin 57 positioned below the mold.

During this upward travel of the piston 16, water is prevented from flowing through the bypass passage 50 by the ice plug formed therein during the ice freezing cycle. In order to assure the continued presence of this plug during the period that the piston is moving upwardly to eject and discharge ice pieces from the cavities 7, all or at least a portion of the walls of passage 50 is formed of suitable heat insulating material 82 designed to delay the melting of the ice plug within the passage 50 until such time as the piston has reached its upper position. The piston is held at the top of the stroke due to the pressure of the water introduced into the cylinder 8 from the measuring vessel 41 until the ice in the passage 50 melts. At this point, the flow of water through the passage 50 relieves the hydraulic pressure within the cylinder 8 so that the springs 28 return the piston to its lower position adjacent the bottom wall 19 of the cylinder. During this return movement of the piston, most of the remaining water from the measuring vessel flows through the bypass passage 50, upwardly through the clearance space 70 between the piston and cylinder and through the passages 14 into the mold cavities.

The mold thermostat 34 opens in response to a predetermined elevated temperature of the mold so as to prevent energization of solenoid valve 45 when the slug valve plunger 46 is returned to its normal position by the spring 47. During return movement of plunger 46, a second stop 83 on the arm 55 throws the toggle switch arm 59 out of engagement with contact 68 to de-energize the mold heaters and into engagement with contact 60 whereby the control circuitry for the solenoid valve 45 is reconditioned for operation of the valve upon subsequent closing of the mold heater thermostat 34. Operation of the ice maker through repeated filling, freezing and harvesting cycles is normally continued until such time as the bin switch 56 is opened as a result of the collection of the desired quantity of ice in the storage bin.

While there has been shown and described a specific embodiment of the present invention it will be understood that it is not limited thereto and is intended by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An automatic ice maker comprising:

a freezer mold including a mold cavity and ice ejecting means,

said ejecting means including a hydraulically operated cylinder and piston assembly operable upon movement of said piston from a first position to a second position to eject an ice piece from said cavity, said piston being frozen against movement from its first position by the formation of an ice bond between said cylinder and piston during formation of an ice piece in said cavity,

means for heating said assembly,

water supply means for supplying a volume of water under pressure to said cylinder for moving said piston to its second position upon melting of said ice bond by said heating means,

and means including a passage in said piston plunged by ice formed in said passage during formation of said ice piece and opened by the melting thereof upon movement of said piston to said second position for conveying said volume of water from said cylinder to said cavity.

2. The ice maker of claim 1 wherein said passage in said piston includes insulated walls for delaying the melting of ice formed therein.

3. The ice maker of claim 1 wherein said water supply means comprises a measuring vessel connected to said cylinder and a normally closed valve controlling the flow of water under pressure to said vessel and means operable upon the filling of said vessel with said volume of water for energizing said heating means.

4. The ice maker of claim 3 including means responsive to the formation of an ice piece in said cavity for opening said valve and responsive to the filling of said vessel to close said valve.

5. The ice maker of claim 1 including mold heating means for thawing the bond between said ice piece and said cavity prior to melting of said ice bond between said cylinder and said piston.

6. An automatic ice maker comprising,

a freezer mold including an ice cavity and a cylinder having an upper portion spaced from said cavity by a wall,

said wall having an opening therein connecting said cavity and cylinder,

a piston in said cylinder movable from a normal position adjacent the lower end of said cylinder to an upper position,

water supply means for introducing a volume of water under pressure into said cylinder below said piston,

means operable upon movement of said piston to its upper position for ejecting an ice piece from said cavity,

means including a passage in said piston for conducting said volume of water from said cylinder to said opening,

water in said passage and between said cylinder and piston surfaces being frozen during formation of an ice piece in said cavity,

heating means for thawing the ice bond between said cylinder and piston surfaces to permit said volume of water to move said piston to its upper position to eject said ice piece and thereafter to melt the ice in said passage for the flow of said volume of water from said cylinder into said ice cavity through said opening,

and means for returning said piston to its normal position.

7. The ice maker of claim 6 in which said water supply means comprises a measuring vessel connected to said cylinder and a normally closed valve controlling the flow of water under pressure to said vessel and means operable upon the filling of said vessel with said volume of water for energizing said heating means.

8. The ice maker of claim 6 including means responsive to the formation of an ice piece in said cavity for opening said valve and responsive to the filling of said vessel to close said valve.

9. An automatic ice maker comprising:

a freezer mold including a vertical cylinder and at least one cavity for the formation of an ice body therein,

said cylinder having an open top end,

said cavity being spaced from the upper portion of said cylinder by a wall having a slot therein connecting said cavity and said cylinder upper portion,

a piston in said cylinder movable between a lower position in which the bottom end of said piston is adjacent to but spaced from the bottom end wall of said cylinder and an upper position in which the top end of said piston projects above the top end of said cylinder,

said piston being spaced from said cylinder to provide a space for the formation of an ice bond therebetween during the formation of an ice body in said cavity,

spring means biasing said piston to its lower position,

an ejection pad in said cavity and means extending through said slot and operatively connecting said pad to said piston for raising said pad and ejecting an ice body from said cavity upon movement of said piston to its upper position,

a sweep operable upon movement of said piston to its upper position to discharge said ice body from said mold,

water supply means for introducing a measured volume of water into said mold comprising a measuring vessel and a supply line connecting said vessel to said cylinder below said piston,

a normally closed valve controlling the flow of water under pressure to said measuring vessel,

means comprising an insulated passage in said piston for conducting water from said cylinder to said slot for flow into said cavity, said passage having its inlet in the lower end of said piston spaced from the edges thereof and its outlet terminating in a cylindrical wall portion of said piston spaced from the lower end thereof, said passage being filled with ice during freezing of water in said cavity,

means for heating said cavity,

means for heating said cylinder,

and means including control circuitry for controlling the operation of said ice maker through a sequence of operations including:

means responsive to the formation of an ice body in said cavity for opening of said normally closed valve to supply said measured volume of water to said vessel,

means responsive to the filling of said vessel for closing valve,

and means for energizing said cavity and cylinder heaters whereby pressure of the water in said measuring vessel moves said piston and pad to their upper positions against the biasing action of said spring to eject said ice body from said cavity and actuate said sweep and discharge said ice piece from said mold,

and melting of the ice in said piston passage permits 7 the flow of water from said cylinder to said cavity during return movement of said piston to its lower position.

References Cited by the Examiner UNITED STATES PATENTS 2,947,156 8/1960 Roedter 62-137 X 3,163,017 12/1964 Baker et a1. 62-137 3,164,968 1/1965 Mullins 62l37 X 3,228,202 1/1966 Cornelius 62-347 X References Cited by the Applicant UNITED STATES PATENTS 1,870,370 8/1932 Merchant.

2,374,997 5/1945 Hill.

3,163,018 12/1964 Shaw.

MEYER PERLIN, Primary Examiner.

ROBERT A. OLEARY, Examiner.

W. E. WAYNER, Assistant Examiner. 

1. AN AUTOMATIC ICE MAKER COMPRISING: A FREEZER MOLD INCLUDING A MOLD CAVITY AND ICE EJECTING MEANS, SAID EJECTING MEANS INCLUDING A HYDRAULICALLY OPERATED CYLINDER AND PISTON ASSEMBLY OPERABLE UPON MOVEMENT OF SAID PISTON FROM A FIRST POSITION TO A SECOND POSITION TO EJECT AN ICE PIECE FROM SAID CAVITY, SAID PISTON BEING FROZEN AGAINST MOVEMENT FROM ITS FIRST POSITION BY THE FORMATION OF AN ICE BOND BETWEEN SAID CYLINDER AND PISTON DURING FORMATION OF AN ICE PIECE IN SAID CAVITY, MEANS FOR HEATING SAID ASSEMBLY, WATER SUPPLY MEANS FOR SUPPLYING A VOLUME OF WATER UNDER PRESSURE TO SAID CYLINDER FOR MOVING SAID PISTON TO ITS SECOND POSITION UPON MELTING OF SAID ICE BOND BY SAID HEATING MEANS, AND MEANS INCLUDING A PASSAGE IN SAID PISTON PLUNGED BY ICE FORMED IN SAID PASSAGE DURING FORMATION OF SAID ICE PIECE AND OPENED BY THE MELTING THEREOF UPON MOVEMENT OF SAID PISTON TO SAID SECOND POSITION FOR CONVEYING SAID VOLUME OF WATER FROM SAID CYLINDER TO SAID CAVITY. 